Remove IMoveSpeedModifier in favor of events (#5212)

* Remove IMoveSpeedModifier

* fucking magboots

* yope

* rabiews

Content.Client/Clothing/MagbootsSystem.cs

@@ -0,0 +1,21 @@
+using Content.Shared.Clothing;
+using Content.Shared.Movement.EntitySystems;
+using Robust.Shared.GameObjects;
+
+namespace Content.Client.Clothing
+{
+    public class MagbootsSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<MagbootsComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
+        }
+
+        private void OnRefreshMovespeed(EntityUid uid, MagbootsComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            args.ModifySpeed(component.WalkSpeedModifier, component.SprintSpeedModifier);
+        }
+    }
+}

Content.Client/Inventory/ClientInventoryComponent.cs

@@ -3,8 +3,10 @@ using System.Diagnostics.CodeAnalysis;
 using System.Linq;
 using Content.Client.Clothing;
 using Content.Shared.CharacterAppearance;
+using Content.Shared.Chemistry;
 using Content.Shared.Inventory;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Robust.Client.GameObjects;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -81,46 +83,6 @@ namespace Content.Client.Inventory
             return item != null && _slots.Values.Any(e => e == item);
         }
 
-        public override float WalkSpeedModifier
-        {
-            get
-            {
-                var mod = 1f;
-                foreach (var slot in _slots.Values)
-                {
-                    if (slot != null)
-                    {
-                        foreach (var modifier in slot.GetAllComponents<IMoveSpeedModifier>())
-                        {
-                            mod *= modifier.WalkSpeedModifier;
-                        }
-                    }
-                }
-
-                return mod;
-            }
-        }
-
-        public override float SprintSpeedModifier
-        {
-            get
-            {
-                var mod = 1f;
-                foreach (var slot in _slots.Values)
-                {
-                    if (slot != null)
-                    {
-                        foreach (var modifier in slot.GetAllComponents<IMoveSpeedModifier>())
-                        {
-                            mod *= modifier.SprintSpeedModifier;
-                        }
-                    }
-                }
-
-                return mod;
-            }
-        }
-
         public override void HandleComponentState(ComponentState? curState, ComponentState? nextState)
         {
             base.HandleComponentState(curState, nextState);
@@ -161,10 +123,7 @@ namespace Content.Client.Inventory
                 }
             }
 
-            if (Owner.TryGetComponent(out MovementSpeedModifierComponent? mod))
+            EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
-            {
-                mod.RefreshMovementSpeedModifiers();
-            }
         }
 
         private void _setSlot(Slots slot, IEntity entity)

Content.Client/Inventory/ClientInventorySystem.cs

@@ -2,6 +2,7 @@ using Content.Client.HUD;
 using Content.Client.Items.Components;
 using Content.Shared.Input;
 using Content.Shared.Inventory;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Slippery;
 using JetBrains.Annotations;
 using Robust.Client.GameObjects;
@@ -29,6 +30,7 @@ namespace Content.Client.Inventory
             SubscribeLocalEvent<ClientInventoryComponent, PlayerDetachedEvent>((_, component, _) => component.PlayerDetached());
 
             SubscribeLocalEvent<ClientInventoryComponent, SlipAttemptEvent>(OnSlipAttemptEvent);
+            SubscribeLocalEvent<ClientInventoryComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
         }
 
         // jesus christ, this is duplicated to server/client, should really just be shared..
@@ -40,6 +42,17 @@ namespace Content.Client.Inventory
             }
         }
 
+        private void OnRefreshMovespeed(EntityUid uid, ClientInventoryComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            foreach (var (_, ent) in component.AllSlots)
+            {
+                if (ent != null)
+                {
+                    RaiseLocalEvent(ent.Uid, args, false);
+                }
+            }
+        }
+
         public override void Shutdown()
         {
             CommandBinds.Unregister<ClientInventorySystem>();

Content.Client/Nutrition/Components/HungerComponent.cs

@@ -1,4 +1,5 @@
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Nutrition.Components;
 using Robust.Shared.GameObjects;
 
@@ -21,10 +22,7 @@ namespace Content.Client.Nutrition.Components
 
             _currentHungerThreshold = hunger.CurrentThreshold;
 
-            if (Owner.TryGetComponent(out MovementSpeedModifierComponent? movement))
+            EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
-            {
-                movement.RefreshMovementSpeedModifiers();
-            }
         }
     }
 }

Content.Client/Nutrition/Components/ThirstComponent.cs

@@ -1,4 +1,5 @@
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Nutrition.Components;
 using Robust.Shared.GameObjects;
 
@@ -21,10 +22,7 @@ namespace Content.Client.Nutrition.Components
 
             _currentThirstThreshold = thirst.CurrentThreshold;
 
-            if (Owner.TryGetComponent(out MovementSpeedModifierComponent? movement))
+            EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
-            {
-                movement.RefreshMovementSpeedModifiers();
-            }
         }
     }
 }

Content.Server/Chemistry/ReagentEffects/MovespeedModifier.cs

@@ -2,6 +2,7 @@ using System;
 using Content.Shared.Chemistry.Components;
 using Content.Shared.Chemistry.Reagent;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
 using Robust.Shared.Serialization.Manager.Attributes;
@@ -38,8 +39,6 @@ namespace Content.Server.Chemistry.ReagentEffects
         /// </summary>
         public override void Metabolize(IEntity solutionEntity, Solution.ReagentQuantity amount)
         {
-            if (!solutionEntity.TryGetComponent(out MovementSpeedModifierComponent? movement)) return;
-
             solutionEntity.EnsureComponent(out MovespeedModifierMetabolismComponent status);
 
             // Only refresh movement if we need to.
@@ -52,7 +51,7 @@ namespace Content.Server.Chemistry.ReagentEffects
             IncreaseTimer(status, StatusLifetime * amount.Quantity.Float());
 
             if (modified)
-                movement.RefreshMovementSpeedModifiers();
+                EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(solutionEntity.Uid);
 
         }
         public void IncreaseTimer(MovespeedModifierMetabolismComponent status, float time)

Content.Server/Clothing/MagbootsSystem.cs

@@ -1,4 +1,5 @@
 using Content.Server.Clothing.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Slippery;
 using Content.Shared.Verbs;
 using Robust.Shared.GameObjects;
@@ -14,6 +15,12 @@ namespace Content.Server.Clothing
 
             SubscribeLocalEvent<MagbootsComponent, GetActivationVerbsEvent>(AddToggleVerb);
             SubscribeLocalEvent<MagbootsComponent, SlipAttemptEvent>(OnSlipAttempt);
+            SubscribeLocalEvent<MagbootsComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
+        }
+
+        private void OnRefreshMovespeed(EntityUid uid, MagbootsComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            args.ModifySpeed(component.WalkSpeedModifier, component.SprintSpeedModifier);
         }
 
         private void AddToggleVerb(EntityUid uid, MagbootsComponent component, GetActivationVerbsEvent args)

Content.Server/Inventory/Components/InventoryComponent.cs

@@ -12,6 +12,7 @@ using Content.Shared.ActionBlocker;
 using Content.Shared.Acts;
 using Content.Shared.Inventory;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Popups;
 using Content.Shared.Verbs;
 using Robust.Server.Console;
@@ -60,46 +61,6 @@ namespace Content.Server.Inventory.Components
             }
         }
 
-        public override float WalkSpeedModifier
-        {
-            get
-            {
-                var mod = 1f;
-                foreach (var slot in _slotContainers.Values)
-                {
-                    if (slot.ContainedEntity != null)
-                    {
-                        foreach (var modifier in slot.ContainedEntity.GetAllComponents<IMoveSpeedModifier>())
-                        {
-                            mod *= modifier.WalkSpeedModifier;
-                        }
-                    }
-                }
-
-                return mod;
-            }
-        }
-
-        public override float SprintSpeedModifier
-        {
-            get
-            {
-                var mod = 1f;
-                foreach (var slot in _slotContainers.Values)
-                {
-                    if (slot.ContainedEntity != null)
-                    {
-                        foreach (var modifier in slot.ContainedEntity.GetAllComponents<IMoveSpeedModifier>())
-                        {
-                            mod *= modifier.SprintSpeedModifier;
-                        }
-                    }
-                }
-
-                return mod;
-            }
-        }
-
         protected override void OnRemove()
         {
             var slots = _slotContainers.Keys.ToList();
@@ -333,10 +294,7 @@ namespace Content.Server.Inventory.Components
 
         private void UpdateMovementSpeed()
         {
-            if (Owner.TryGetComponent(out MovementSpeedModifierComponent? mod))
+            EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
-            {
-                mod.RefreshMovementSpeedModifiers();
-            }
         }
 
         public void ForceUnequip(Slots slot)

Content.Server/Inventory/InventorySystem.cs

@@ -5,6 +5,7 @@ using Content.Shared.Inventory;
 using Content.Shared.Slippery;
 using Content.Shared.Damage;
 using Content.Shared.Electrocution;
+using Content.Shared.Movement.EntitySystems;
 using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
 
@@ -23,6 +24,7 @@ namespace Content.Server.Inventory
             SubscribeLocalEvent<InventoryComponent, DamageModifyEvent>(OnDamageModify);
             SubscribeLocalEvent<InventoryComponent, ElectrocutionAttemptEvent>(OnElectrocutionAttempt);
             SubscribeLocalEvent<InventoryComponent, SlipAttemptEvent>(OnSlipAttemptEvent);
+            SubscribeLocalEvent<InventoryComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
         }
 
         private void OnSlipAttemptEvent(EntityUid uid, InventoryComponent component, SlipAttemptEvent args)
@@ -33,6 +35,11 @@ namespace Content.Server.Inventory
             }
         }
 
+        private void OnRefreshMovespeed(EntityUid uid, InventoryComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            RelayInventoryEvent(component, args);
+        }
+
         private static void HandleInvRemovedFromContainer(EntityUid uid, InventoryComponent component, EntRemovedFromContainerMessage args)
         {
             component.ForceUnequip(args.Container, args.Entity);
@@ -45,31 +52,25 @@ namespace Content.Server.Inventory
 
         private void OnHighPressureEvent(EntityUid uid, InventoryComponent component, HighPressureEvent args)
         {
-            RelayPressureEvent(component, args);
+            RelayInventoryEvent(component, args);
         }
 
         private void OnLowPressureEvent(EntityUid uid, InventoryComponent component, LowPressureEvent args)
         {
-            RelayPressureEvent(component, args);
+            RelayInventoryEvent(component, args);
         }
 
         private void OnElectrocutionAttempt(EntityUid uid, InventoryComponent component, ElectrocutionAttemptEvent args)
         {
-            foreach (var equipped in component.GetAllHeldItems())
+            RelayInventoryEvent(component, args);
-            {
-                RaiseLocalEvent(equipped.Uid, args, false);
-            }
         }
 
         private void OnDamageModify(EntityUid uid, InventoryComponent component, DamageModifyEvent args)
         {
-            foreach (var equipped in component.GetAllHeldItems())
+            RelayInventoryEvent(component, args);
-            {
-                RaiseLocalEvent(equipped.Uid, args, false);
-            }
         }
 
-        private void RelayPressureEvent<T>(InventoryComponent component, T args) where T : PressureEvent
+        private void RelayInventoryEvent<T>(InventoryComponent component, T args) where T : EntityEventArgs
         {
             foreach (var equipped in component.GetAllHeldItems())
             {

Content.Server/Nutrition/Components/HungerComponent.cs

@@ -5,6 +5,7 @@ using Content.Shared.Alert;
 using Content.Shared.Damage;
 using Content.Shared.MobState;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Nutrition.Components;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -86,7 +87,7 @@ namespace Content.Server.Nutrition.Components
                 if (_lastHungerThreshold == HungerThreshold.Starving && _currentHungerThreshold != HungerThreshold.Dead &&
                     Owner.TryGetComponent(out MovementSpeedModifierComponent? movementSlowdownComponent))
                 {
-                    movementSlowdownComponent.RefreshMovementSpeedModifiers();
+                    EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
                 }
 
                 // Update UI
@@ -122,10 +123,7 @@ namespace Content.Server.Nutrition.Components
                     case HungerThreshold.Starving:
                         // TODO: If something else bumps this could cause mega-speed.
                         // If some form of speed update system if multiple things are touching it use that.
-                        if (Owner.TryGetComponent(out MovementSpeedModifierComponent? movementSlowdownComponent1))
+                        EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
-                        {
-                            movementSlowdownComponent1.RefreshMovementSpeedModifiers();
-                        }
                         _lastHungerThreshold = _currentHungerThreshold;
                         _actualDecayRate = _baseDecayRate * 0.6f;
                         return;

Content.Server/Nutrition/Components/ThirstComponent.cs

@@ -5,6 +5,7 @@ using Content.Shared.Alert;
 using Content.Shared.Damage;
 using Content.Shared.MobState;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Nutrition.Components;
 using Robust.Shared.GameObjects;
 using Robust.Shared.IoC;
@@ -85,7 +86,7 @@ namespace Content.Server.Nutrition.Components
                 if (_lastThirstThreshold == ThirstThreshold.Parched && _currentThirstThreshold != ThirstThreshold.Dead &&
                     Owner.TryGetComponent(out MovementSpeedModifierComponent? movementSlowdownComponent))
                 {
-                    movementSlowdownComponent.RefreshMovementSpeedModifiers();
+                    EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
                 }
 
                 // Update UI
@@ -119,10 +120,7 @@ namespace Content.Server.Nutrition.Components
                         return;
 
                     case ThirstThreshold.Parched:
-                        if (Owner.TryGetComponent(out MovementSpeedModifierComponent? movementSlowdownComponent1))
+                        EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(OwnerUid);
-                        {
-                            movementSlowdownComponent1.RefreshMovementSpeedModifiers();
-                        }
                         _lastThirstThreshold = _currentThirstThreshold;
                         _actualDecayRate = _baseDecayRate * 0.6f;
                         return;

Content.Server/Stunnable/StunOnCollideSystem.cs

@@ -34,10 +34,9 @@ namespace Content.Server.Stunnable
                 ServerAlertsComponent? alerts = null;
                 StandingStateComponent? standingState = null;
                 AppearanceComponent? appearance = null;
-                MovementSpeedModifierComponent? speedModifier = null;
 
                 // Let the actual methods log errors for these.
-                Resolve(otherUid, ref alerts, ref standingState, ref appearance, ref speedModifier, false);
+                Resolve(otherUid, ref alerts, ref standingState, ref appearance, false);
 
                 _stunSystem.TryStun(otherUid, TimeSpan.FromSeconds(component.StunAmount), status, alerts);
 
@@ -45,7 +44,7 @@ namespace Content.Server.Stunnable
                     status, alerts);
 
                 _stunSystem.TrySlowdown(otherUid, TimeSpan.FromSeconds(component.SlowdownAmount),
-                    component.WalkSpeedMultiplier, component.RunSpeedMultiplier, status, speedModifier, alerts);
+                    component.WalkSpeedMultiplier, component.RunSpeedMultiplier, status, alerts);
             }
         }
     }

Content.Shared/Chemistry/Components/MovespeedModifierMetabolismComponent.cs

@@ -4,6 +4,7 @@ using Robust.Shared.Players;
 using Robust.Shared.Serialization;
 using Robust.Shared.ViewVariables;
 using System;
+using Robust.Shared.Analyzers;
 using Robust.Shared.GameStates;
 using Robust.Shared.Timing;
 using Robust.Shared.IoC;
@@ -13,7 +14,7 @@ namespace Content.Shared.Chemistry.Components
     //TODO: refactor movement modifier component because this is a pretty poor solution
     [RegisterComponent]
     [NetworkedComponent]
-    public sealed class MovespeedModifierMetabolismComponent : Component, IMoveSpeedModifier
+    public sealed class MovespeedModifierMetabolismComponent : Component
     {
         [ViewVariables]
         public override string Name => "MovespeedModifierMetabolism";

Content.Shared/Chemistry/MetabolismMovespeedModifierSystem.cs

@@ -6,13 +6,16 @@ using Robust.Shared.Timing;
 using System.Collections.Generic;
 using System.Linq;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using static Content.Shared.Chemistry.Components.MovespeedModifierMetabolismComponent;
 
 namespace Content.Shared.Chemistry
 {
+    // TODO CONVERT THIS TO A STATUS EFFECT!!!!!!!!!!!!!!!!!!!!!!!!
     public class MetabolismMovespeedModifierSystem : EntitySystem
     {
         [Dependency] private readonly IGameTiming _gameTiming = default!;
+        [Dependency] private readonly MovementSpeedModifierSystem _movespeed = default!;
 
         private readonly List<MovespeedModifierMetabolismComponent> _components = new();
 
@@ -22,6 +25,7 @@ namespace Content.Shared.Chemistry
 
             SubscribeLocalEvent<MovespeedModifierMetabolismComponent, ComponentHandleState>(OnMovespeedHandleState);
             SubscribeLocalEvent<MovespeedModifierMetabolismComponent, ComponentStartup>(AddComponent);
+            SubscribeLocalEvent<MovespeedModifierMetabolismComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
         }
 
         private void OnMovespeedHandleState(EntityUid uid, MovespeedModifierMetabolismComponent component, ref ComponentHandleState args)
@@ -33,7 +37,7 @@ namespace Content.Shared.Chemistry
                 (!component.WalkSpeedModifier.Equals(cast.WalkSpeedModifier) ||
                  !component.SprintSpeedModifier.Equals(cast.SprintSpeedModifier)))
             {
-                modifier.RefreshMovementSpeedModifiers();
+                _movespeed.RefreshMovementSpeedModifiers(uid);
             }
 
             component.WalkSpeedModifier = cast.WalkSpeedModifier;
@@ -41,6 +45,12 @@ namespace Content.Shared.Chemistry
             component.ModifierTimer = cast.ModifierTimer;
 
         }
+
+        private void OnRefreshMovespeed(EntityUid uid, MovespeedModifierMetabolismComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            args.ModifySpeed(component.WalkSpeedModifier, component.SprintSpeedModifier);
+        }
+
         private void AddComponent(EntityUid uid, MovespeedModifierMetabolismComponent component, ComponentStartup args)
         {
             _components.Add(component);
@@ -65,12 +75,9 @@ namespace Content.Shared.Chemistry
                 if (component.ModifierTimer > currentTime) continue;
 
                 _components.RemoveAt(i);
-                EntityManager.RemoveComponent<MovespeedModifierMetabolismComponent>(component.Owner.Uid);
+                EntityManager.RemoveComponent<MovespeedModifierMetabolismComponent>(component.OwnerUid);
 
-                if (component.Owner.TryGetComponent(out MovementSpeedModifierComponent? modifier))
+                _movespeed.RefreshMovementSpeedModifiers(component.OwnerUid);
-                {
-                    modifier.RefreshMovementSpeedModifiers();
-                }
             }
         }
     }

Content.Shared/Clothing/SharedMagbootsComponent.cs

@@ -1,5 +1,7 @@
 using System;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
+using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
 using Robust.Shared.Serialization;
@@ -7,16 +9,19 @@ using Robust.Shared.Serialization;
 namespace Content.Shared.Clothing
 {
     [NetworkedComponent()]
-    public abstract class SharedMagbootsComponent : Component, IMoveSpeedModifier
+    public abstract class SharedMagbootsComponent : Component
     {
         public sealed override string Name => "Magboots";
 
         public abstract bool On { get; set; }
 
-
         protected void OnChanged()
         {
-            MovementSpeedModifierComponent.RefreshItemModifiers(Owner);
+            // inventory system will automatically hook into the event raised by this and update accordingly
+            if (Owner.TryGetContainer(out var container))
+            {
+                EntitySystem.Get<MovementSpeedModifierSystem>().RefreshMovementSpeedModifiers(container.Owner.Uid);
+            }
         }
 
         public float WalkSpeedModifier => On ? 0.85f : 1;

Content.Shared/Inventory/SharedInventoryComponent.cs

@@ -14,7 +14,7 @@ using static Content.Shared.Inventory.EquipmentSlotDefines;
 namespace Content.Shared.Inventory
 {
     [NetworkedComponent()]
-    public abstract class SharedInventoryComponent : Component, IMoveSpeedModifier
+    public abstract class SharedInventoryComponent : Component
     {
         [Dependency] protected readonly IReflectionManager ReflectionManager = default!;
         [Dependency] protected readonly IDynamicTypeFactory DynamicTypeFactory = default!;
@@ -98,8 +98,5 @@ namespace Content.Shared.Inventory
                 Slot = slot;
             }
         }
-
-        public abstract float WalkSpeedModifier { get; }
-        public abstract float SprintSpeedModifier { get; }
     }
 }

Content.Shared/Movement/Components/MovementSpeedModifierComponent.cs

@@ -1,3 +1,5 @@
+using Content.Shared.Movement.EntitySystems;
+using Robust.Shared.Analyzers;
 using Robust.Shared.Containers;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
@@ -7,7 +9,7 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Movement.Components
 {
     [RegisterComponent]
-    [NetworkedComponent]
+    [NetworkedComponent, Friend(typeof(MovementSpeedModifierSystem))]
     public sealed class MovementSpeedModifierComponent : Component
     {
         public const float DefaultBaseWalkSpeed = 4.0f;
@@ -15,26 +17,11 @@ namespace Content.Shared.Movement.Components
 
         public override string Name => "MovementSpeedModifier";
 
-        private float _cachedWalkSpeedModifier = 1.0f;
         [ViewVariables]
-        public float WalkSpeedModifier
+        public float WalkSpeedModifier = 1.0f;
-        {
+
-            get
-            {
-                RecalculateMovementSpeedModifiers();
-                return _cachedWalkSpeedModifier;
-            }
-        }
-        private float _cachedSprintSpeedModifier;
         [ViewVariables]
-        public float SprintSpeedModifier
+        public float SprintSpeedModifier = 1.0f;
-        {
-            get
-            {
-                RecalculateMovementSpeedModifiers();
-                return _cachedSprintSpeedModifier;
-            }
-        }
 
         [ViewVariables(VVAccess.ReadWrite)]
         public float BaseWalkSpeedVV
@@ -68,52 +55,5 @@ namespace Content.Shared.Movement.Components
         public float CurrentWalkSpeed => WalkSpeedModifier * BaseWalkSpeed;
         [ViewVariables]
         public float CurrentSprintSpeed => SprintSpeedModifier * BaseSprintSpeed;
-
-        /// <summary>
-        ///     set to warn us that a component's movespeed modifier has changed
-        /// </summary>
-        private bool _movespeedModifiersNeedRefresh = true;
-
-        public void RefreshMovementSpeedModifiers()
-        {
-            _movespeedModifiersNeedRefresh = true;
-        }
-
-        public static void RefreshItemModifiers(IEntity item)
-        {
-            if (item.TryGetContainer(out var container) &&
-                container.Owner.TryGetComponent(out MovementSpeedModifierComponent? mod))
-            {
-                mod.RefreshMovementSpeedModifiers();
-            }
-        }
-
-        /// <summary>
-        ///     Recalculate movement speed with current modifiers, or return early if no change
-        /// </summary>
-        private void RecalculateMovementSpeedModifiers()
-        {
-            {
-                if (!_movespeedModifiersNeedRefresh)
-                    return;
-                var movespeedModifiers = Owner.GetAllComponents<IMoveSpeedModifier>();
-                float walkSpeedModifier = 1.0f;
-                float sprintSpeedModifier = 1.0f;
-                foreach (var component in movespeedModifiers)
-                {
-                    walkSpeedModifier *= component.WalkSpeedModifier;
-                    sprintSpeedModifier *= component.SprintSpeedModifier;
-                }
-                _cachedWalkSpeedModifier = walkSpeedModifier;
-                _cachedSprintSpeedModifier = sprintSpeedModifier;
-            }
-            _movespeedModifiersNeedRefresh = false;
-        }
-    }
-
-    public interface IMoveSpeedModifier
-    {
-        float WalkSpeedModifier { get; }
-        float SprintSpeedModifier { get; }
     }
 }

Content.Shared/Movement/EntitySystems/MovementSpeedModifierSystem.cs

@@ -1,4 +1,6 @@
 using System;
+using System.Collections.Generic;
+using System.Linq;
 using Content.Shared.Movement.Components;
 using Robust.Shared.GameObjects;
 using Robust.Shared.GameStates;
@@ -8,6 +10,18 @@ namespace Content.Shared.Movement.EntitySystems
 {
     public sealed class MovementSpeedModifierSystem : EntitySystem
     {
+        private readonly HashSet<EntityUid> _needsRefresh = new();
+
+        public override void Update(float frameTime)
+        {
+            foreach (var uid in _needsRefresh)
+            {
+                RecalculateMovementSpeedModifiers(uid);
+            }
+
+            _needsRefresh.Clear();
+        }
+
         public override void Initialize()
         {
             base.Initialize();
@@ -31,6 +45,25 @@ namespace Content.Shared.Movement.EntitySystems
             component.BaseSprintSpeed = state.BaseSprintSpeed;
         }
 
+        public void RefreshMovementSpeedModifiers(EntityUid uid)
+        {
+            _needsRefresh.Add(uid);
+        }
+
+        private void RecalculateMovementSpeedModifiers(EntityUid uid, MovementSpeedModifierComponent? move = null)
+        {
+            if (!Resolve(uid, ref move, false))
+                return;
+
+            var ev = new RefreshMovementSpeedModifiersEvent();
+            RaiseLocalEvent(uid, ev, false);
+
+            move.WalkSpeedModifier = ev.WalkSpeedModifier;
+            move.SprintSpeedModifier = ev.SprintSpeedModifier;
+
+            move.Dirty();
+        }
+
         [Serializable, NetSerializable]
         private sealed class MovementSpeedModifierComponentState : ComponentState
         {
@@ -38,4 +71,21 @@ namespace Content.Shared.Movement.EntitySystems
             public float BaseSprintSpeed;
         }
     }
+
+    /// <summary>
+    ///     Raised on an entity to determine its new movement speed. Any system that wishes to change movement speed
+    ///     should hook into this event and set it then. If you want this event to be raised,
+    ///     call <see cref="MovementSpeedModifierSystem.RefreshMovementSpeedModifiers"/>.
+    /// </summary>
+    public class RefreshMovementSpeedModifiersEvent : EntityEventArgs
+    {
+        public float WalkSpeedModifier { get; private set; } = 1.0f;
+        public float SprintSpeedModifier { get; private set; } = 1.0f;
+
+        public void ModifySpeed(float walk, float sprint)
+        {
+            WalkSpeedModifier *= walk;
+            SprintSpeedModifier *= sprint;
+        }
+    }
 }

Content.Shared/Nutrition/Components/SharedHungerComponent.cs

@@ -8,37 +8,13 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Nutrition.Components
 {
     [NetworkedComponent()]
-    public abstract class SharedHungerComponent : Component, IMoveSpeedModifier
+    public abstract class SharedHungerComponent : Component
     {
         public sealed override string Name => "Hunger";
 
         [ViewVariables]
         public abstract HungerThreshold CurrentHungerThreshold { get; }
 
-
-        float IMoveSpeedModifier.WalkSpeedModifier
-        {
-            get
-            {
-                if (CurrentHungerThreshold == HungerThreshold.Starving)
-                {
-                    return 0.75f;
-                }
-                return 1.0f;
-            }
-        }
-        float IMoveSpeedModifier.SprintSpeedModifier
-        {
-            get
-            {
-                if (CurrentHungerThreshold == HungerThreshold.Starving)
-                {
-                    return 0.75f;
-                }
-                return 1.0f;
-            }
-        }
-
         [Serializable, NetSerializable]
         protected sealed class HungerComponentState : ComponentState
         {

Content.Shared/Nutrition/Components/SharedThirstComponent.cs

@@ -8,36 +8,13 @@ using Robust.Shared.ViewVariables;
 namespace Content.Shared.Nutrition.Components
 {
     [NetworkedComponent()]
-    public abstract class SharedThirstComponent : Component, IMoveSpeedModifier
+    public abstract class SharedThirstComponent : Component
     {
         public sealed override string Name => "Thirst";
 
         [ViewVariables]
         public abstract ThirstThreshold CurrentThirstThreshold { get; }
 
-        float IMoveSpeedModifier.SprintSpeedModifier
-        {
-            get
-            {
-                if (CurrentThirstThreshold == ThirstThreshold.Parched)
-                {
-                    return 0.75f;
-                }
-                return 1.0f;
-            }
-        }
-        float IMoveSpeedModifier.WalkSpeedModifier
-        {
-            get
-            {
-                if (CurrentThirstThreshold == ThirstThreshold.Parched)
-                {
-                    return 0.75f;
-                }
-                return 1.0f;
-            }
-        }
-
         [Serializable, NetSerializable]
         protected sealed class ThirstComponentState : ComponentState
         {

Content.Shared/Nutrition/EntitySystems/SharedHungerSystem.cs

@@ -0,0 +1,22 @@
+using Content.Shared.Movement.EntitySystems;
+using Content.Shared.Nutrition.Components;
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.Nutrition.EntitySystems
+{
+    public class SharedHungerSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<SharedHungerComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
+        }
+
+        private void OnRefreshMovespeed(EntityUid uid, SharedHungerComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            float mod = component.CurrentHungerThreshold == HungerThreshold.Starving ? 0.75f : 1.0f;
+            args.ModifySpeed(mod, mod);
+        }
+    }
+}

Content.Shared/Nutrition/EntitySystems/SharedThirstSystem.cs

@@ -0,0 +1,22 @@
+using Content.Shared.Movement.EntitySystems;
+using Content.Shared.Nutrition.Components;
+using Robust.Shared.GameObjects;
+
+namespace Content.Shared.Nutrition.EntitySystems
+{
+    public class SharedThirstSystem : EntitySystem
+    {
+        public override void Initialize()
+        {
+            base.Initialize();
+
+            SubscribeLocalEvent<SharedThirstComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
+        }
+
+        private void OnRefreshMovespeed(EntityUid uid, SharedThirstComponent component, RefreshMovementSpeedModifiersEvent args)
+        {
+            float mod = component.CurrentThirstThreshold == ThirstThreshold.Parched ? 0.75f : 1.0f;
+            args.ModifySpeed(mod, mod);
+        }
+    }
+}

Content.Shared/Pulling/Components/SharedPullerComponent.cs

@@ -10,7 +10,7 @@ namespace Content.Shared.Pulling.Components
 {
     [RegisterComponent]
     [Friend(typeof(SharedPullingStateManagementSystem))]
-    public class SharedPullerComponent : Component, IMoveSpeedModifier
+    public class SharedPullerComponent : Component
     {
         public override string Name => "Puller";
 

Content.Shared/Pulling/Systems/SharedPullerSystem.cs

@@ -1,6 +1,7 @@
 using Content.Shared.Alert;
 using Content.Shared.Hands;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Physics.Pull;
 using Content.Shared.Pulling.Components;
 using JetBrains.Annotations;
@@ -13,6 +14,7 @@ namespace Content.Shared.Pulling.Systems
     public sealed class SharedPullerSystem : EntitySystem
     {
         [Dependency] private readonly SharedPullingSystem _pullSystem = default!;
+        [Dependency] private readonly MovementSpeedModifierSystem _movementSpeedModifierSystem = default!;
 
         public override void Initialize()
         {
@@ -21,6 +23,7 @@ namespace Content.Shared.Pulling.Systems
             SubscribeLocalEvent<SharedPullerComponent, PullStartedMessage>(PullerHandlePullStarted);
             SubscribeLocalEvent<SharedPullerComponent, PullStoppedMessage>(PullerHandlePullStopped);
             SubscribeLocalEvent<SharedPullerComponent, VirtualItemDeletedEvent>(OnVirtualItemDeleted);
+            SubscribeLocalEvent<SharedPullerComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
         }
 
         private void OnVirtualItemDeleted(EntityUid uid, SharedPullerComponent component, VirtualItemDeletedEvent args)
@@ -37,7 +40,7 @@ namespace Content.Shared.Pulling.Systems
             }
         }
 
-        private static void PullerHandlePullStarted(
+        private void PullerHandlePullStarted(
             EntityUid uid,
             SharedPullerComponent component,
             PullStartedMessage args)
@@ -51,7 +54,7 @@ namespace Content.Shared.Pulling.Systems
             RefreshMovementSpeed(component);
         }
 
-        private static void PullerHandlePullStopped(
+        private void PullerHandlePullStopped(
             EntityUid uid,
             SharedPullerComponent component,
             PullStoppedMessage args)
@@ -65,13 +68,14 @@ namespace Content.Shared.Pulling.Systems
             RefreshMovementSpeed(component);
         }
 
-        private static void RefreshMovementSpeed(SharedPullerComponent component)
+        private void OnRefreshMovespeed(EntityUid uid, SharedPullerComponent component, RefreshMovementSpeedModifiersEvent args)
         {
-            // Before changing how this is updated, please see SharedPullerComponent
+            args.ModifySpeed(component.WalkSpeedModifier, component.SprintSpeedModifier);
-            if (component.Owner.TryGetComponent<MovementSpeedModifierComponent>(out var speed))
+        }
-            {
+
-                speed.RefreshMovementSpeedModifiers();
+        private void RefreshMovementSpeed(SharedPullerComponent component)
-            }
+        {
+            _movementSpeedModifierSystem.RefreshMovementSpeedModifiers(component.OwnerUid);
         }
     }
 }

Content.Shared/Stunnable/SharedStunSystem.cs

@@ -8,6 +8,7 @@ using Content.Shared.Inventory.Events;
 using Content.Shared.Item;
 using Content.Shared.Movement;
 using Content.Shared.Movement.Components;
+using Content.Shared.Movement.EntitySystems;
 using Content.Shared.Speech;
 using Content.Shared.Standing;
 using Content.Shared.StatusEffect;
@@ -27,6 +28,7 @@ namespace Content.Shared.Stunnable
     {
         [Dependency] private readonly StandingStateSystem _standingStateSystem = default!;
         [Dependency] private readonly StatusEffectsSystem _statusEffectSystem = default!;
+        [Dependency] private readonly MovementSpeedModifierSystem _movementSpeedModifierSystem = default!;
 
         public override void Initialize()
         {
@@ -44,6 +46,7 @@ namespace Content.Shared.Stunnable
 
             // helping people up if they're knocked down
             SubscribeLocalEvent<KnockedDownComponent, InteractHandEvent>(OnInteractHand);
+            SubscribeLocalEvent<SlowedDownComponent, RefreshMovementSpeedModifiersEvent>(OnRefreshMovespeed);
 
             // Attempt event subscriptions.
             SubscribeLocalEvent<StunnedComponent, MovementAttemptEvent>(OnMoveAttempt);
@@ -97,22 +100,17 @@ namespace Content.Shared.Stunnable
 
         private void OnSlowInit(EntityUid uid, SlowedDownComponent component, ComponentInit args)
         {
-            // needs to be done so the client can also refresh when the addition is replicated,
+            _movementSpeedModifierSystem.RefreshMovementSpeedModifiers(uid);
-            // if the initial status effect addition wasn't predicted
-            if (EntityManager.TryGetComponent<MovementSpeedModifierComponent>(uid, out var move))
-            {
-                move.RefreshMovementSpeedModifiers();
-            }
         }
 
         private void OnSlowRemove(EntityUid uid, SlowedDownComponent component, ComponentRemove args)
         {
-            if (EntityManager.TryGetComponent<MovementSpeedModifierComponent>(uid, out var move))
+            _movementSpeedModifierSystem.RefreshMovementSpeedModifiers(uid);
-            {
+        }
-                component.SprintSpeedModifier = 1.0f;
+
-                component.WalkSpeedModifier = 1.0f;
+        private void OnRefreshMovespeed(EntityUid uid, SlowedDownComponent component, RefreshMovementSpeedModifiersEvent args)
-                move.RefreshMovementSpeedModifiers();
+        {
-            }
+            args.ModifySpeed(component.WalkSpeedModifier, component.SprintSpeedModifier);
         }
 
         // TODO STUN: Make events for different things. (Getting modifiers, attempt events, informative events...)
@@ -127,6 +125,9 @@ namespace Content.Shared.Stunnable
             if (time <= TimeSpan.Zero)
                 return false;
 
+            if (!Resolve(uid, ref status, false))
+                return false;
+
             Resolve(uid, ref alerts, false);
 
             return _statusEffectSystem.TryAddStatusEffect<StunnedComponent>(uid, "Stun", time, alerts: alerts);
@@ -142,6 +143,9 @@ namespace Content.Shared.Stunnable
             if (time <= TimeSpan.Zero)
                 return false;
 
+            if (!Resolve(uid, ref status, false))
+                return false;
+
             Resolve(uid, ref alerts, false);
 
             return _statusEffectSystem.TryAddStatusEffect<KnockedDownComponent>(uid, "KnockedDown", time, alerts: alerts);
@@ -154,6 +158,9 @@ namespace Content.Shared.Stunnable
             StatusEffectsComponent? status = null,
             SharedAlertsComponent? alerts = null)
         {
+            if (!Resolve(uid, ref status))
+                return false;
+
             // Optional component.
             Resolve(uid, ref alerts, false);
 
@@ -166,11 +173,13 @@ namespace Content.Shared.Stunnable
         public bool TrySlowdown(EntityUid uid, TimeSpan time,
             float walkSpeedMultiplier = 1f, float runSpeedMultiplier = 1f,
             StatusEffectsComponent? status = null,
-            MovementSpeedModifierComponent? speedModifier = null,
             SharedAlertsComponent? alerts = null)
         {
+            if (!Resolve(uid, ref status))
+                return false;
+
             // "Optional" component.
-            Resolve(uid, ref speedModifier, false);
+            Resolve(uid, ref alerts, false);
 
             if (time <= TimeSpan.Zero)
                 return false;
@@ -185,7 +194,7 @@ namespace Content.Shared.Stunnable
                 slowed.WalkSpeedModifier *= walkSpeedMultiplier;
                 slowed.SprintSpeedModifier *= runSpeedMultiplier;
 
-                speedModifier?.RefreshMovementSpeedModifiers();
+                _movementSpeedModifierSystem.RefreshMovementSpeedModifiers(uid);
 
                 return true;
             }

Content.Shared/Stunnable/SlowedDownComponent.cs

@@ -10,7 +10,7 @@ namespace Content.Shared.Stunnable
     [RegisterComponent]
     [NetworkedComponent]
     [Friend(typeof(SharedStunSystem))]
-    public class SlowedDownComponent : Component, IMoveSpeedModifier
+    public class SlowedDownComponent : Component
     {
         public override string Name => "SlowedDown";